Bone Plate and Plating System for Use of Same

ABSTRACT

A bone plate and plating system are for use of the same are disclosed. The bone plate includes a body having a span sufficient to overlap a portion of a bone. A screw hole extends through the body in order to receive a bone screw to attach for engaging the plate to the bone. The screw hole includes a counterbore having a beveled surface that intersects at a pinch point a bore having a conical surface of revolution that transitions into the bone engaging surface of the body. The beveled surface includes a variable geometry defining interleaved and rotationally-spaced contact and non-contact bone screw regions.

PRIORITY STATEMENT & CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending patent application Ser.No. 12/629,779 entitled “Bone Plate and Plating System for Use of Same,”filed on Dec. 2, 2009, and issued Apr. 1, 2014, as U.S. Pat. No.8,685,069 in the names of Steve Courtney and David Freehill; whichclaims priority from Ser. No. 61/119,324 entitled “Anterior ButtressStaple and Method for Use of Same” and filed on Dec. 2, 2008 in thenames of Steve Courtney and David Freehill; which are herebyincorporated by reference for all purposes.

TECHNICAL FIELD OF THE INVENTION

This invention relates, in general, to medical implants useful fororthopedic surgeries and, in particular, to surgical bone plates andbone plating systems utilizing locking bone screws that fix the boneplate to an aspect of a bone to provide for stabilization thereof.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with spinal implant stabilization of degeneratedintervertebral discs, as an example. When an intervertebral disc issubject to degeneration caused by trauma, disease, and/or aging, forexample, a partial or full removal from the spinal column is oftenrequired. This discectomy creates a void that may result in analteration in the natural separation distance between adjacent vertebraeand an overall destabilization of the spinal column. To maintain thenatural separation between the vertebrae and to help prevent pressurefrom being applied to nerves that pass between vertebral bodies, anintervertebral spinal implant is inserted within the space created bythe removal or partial removal of an intervertebral disc betweenadjacent vertebrae. The spinal implant may maintain the height of thespine and restore stability to the spine. Later and in some instances,intervertebral bone growth may fuse the spinal implant to adjacentvertebrae.

The spinal implant may be inserted during a spinal fixation procedureusing an anterior, lateral, or posterior spinal approach. In somesituations, the anterior approach results in an easier approach, lessmuscle and tissue damage, and/or less bone removal than otherapproaches. Following insertion of the spinal implant, a spinal plate iscoupled to one or more vertebrae in order to stabilize the vertebrae andinhibit backout of the spinal implant from between vertebrae.

Fasteners (e.g., bone screws) may be used to fasten the spinal plate tovertebrae. There exists a continuing need for spinal plates that inhibitbackout while causing minimum damage to the surrounding bone and tissueduring implantation as well as subsequent use following implantation.

SUMMARY OF THE INVENTION

A bone plate and plating system, with locking screw, for use of the sameare disclosed. The bone plate includes a body having a span sufficientto overlap a portion of a bone. A screw hole extends through the body inorder to receive a bone screw to attach for engaging the plate to thebone. The screw hole includes a counterbore having a beveled surfacethat intersects at a pinch point a bore having a conical surface ofrevolution that transitions into the bone engaging surface of the body.The beveled surface includes a variable geometry defining interleavedand rotationally-spaced contact and non-contact bone screw regions.

In the plating system utilizing the bone plate, a screw is employed tobe inserted into the bone. The screw includes a head region configuredto be secured within the screw hole and an elongated body threadedextending therefrom to a distal end of the screw. The screw alsoincludes a proximal root portion at the head region that furnishes asloping radial surface ending in a continuous rib which radiallyprojects from the screw. The pinch point of the screw hole flexiblycaptures the screw to limit axial travel by a detented engagementbetween the pinch point and a junction of the sloping radial surface andthe continuous rib.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is an illustrated view of one embodiment of a bone plating systemimplanted into a human vertebral column;

FIG. 2 is a top plan view of one embodiment of a bone plate which formsa portion of the bone plating system depicted in FIG. 1;

FIG. 3 is a bottom plan view of the bone plate depicted in FIG. 2;

FIG. 4 is a side elevation view of the bone plate depicted in FIG. 2;

FIG. 5 is a side elevation view of one embodiment of a screw for usewith the bone plating system depicted in FIG. 1;

FIG. 6 is a top plan view of the bone plating system depicted in FIG. 1;

FIG. 7 is a bottom plan view of the bone plating system depicted in FIG.1;

FIG. 8 is a cross-sectional view of a portion of the bone plating systemdepicted in FIG. 1 along a 120° section as shown in line 8-8 of FIG. 6to illustrate a locking mechanism;

FIG. 9 is a cross-sectional view of a portion of the bone plating systemdepicted in FIG. 1 along a 180° section as shown in line 9-9 of FIG. 6to illustrate the locking mechanism;

FIG. 10 is a two-dimensional representation of a portion athree-dimensional screw hole depicted in FIGS. 8 and 9;

FIG. 11 is a top plan view of another embodiment of a bone plateaccording to the teachings presented herein;

FIG. 12 is a top plan view of a further embodiment of a bone plateaccording to the teachings presented herein;

FIG. 13 is a side elevation view of the bone plate depicted in FIG. 12;

FIG. 14 is a top plan view of a still further embodiment of a bone plateaccording to the teachings presented herein; and

FIG. 15 is a front perspective view of an additional embodiment of abone plate according to the teachings presented herein.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of the presentinvention.

Referring to FIG. 1, therein is depicted a bone plating system 10, whichfor purposes of explanation, is depicted as including a bone plate thatis schematically illustrated and generally designated 12 and shown as ananterior buttress staple or buttress plate. A bone plate may be arelatively thin metal device which is affixed to bone via screws, suchas screw, which, in one implementation, may be any threaded device ofmetal or other material(s) which is inserted into bone. The bone platemay be used to immobilize bones or bone fragments such that healing canoccur. In this respect, the bone screw engages bones in order toimmobilize bones or bone fragments or to affix other medical devices,such as metal bone plates, to bones. In particular, the bone plate orthe buttress plate 12 in the form of a spinal plate is utilized tosupport the internal stabilization of adjacent vertebral bodies of aspinal column after replacement of an intervertebral disk, for example.As shown, in one operational embodiment, following insertion of a spinalimplant I between vertebrae V, the bone plate 12 is coupled to vertebraV in order to stabilize the vertebrae V and inhibit backout of thespinal implant I from between vertebrae V.

Referring now to FIG. 2 through FIG. 7, the bone plate 12 includes a“figure 8” shaped body having upper and lower body portions 14, 16 eachincluding openings that respectively provide a screw hole 18 and avisualization window 20. The lower body portion 16 further includes abroad span that prevents graft expulsion during use. Additionally, anangle of displacement a between the upper body portion 14 and the lowerbody portion 16 is present to reflect angle of lordosis, such as anangle of cervical lordosis.

The screw hole 18 located at the upper body portion 14 and extendingtherethrough from an upper surface to a lower surface accepts a selftapping screw 30 that is threaded into one of the vertebral bodies,thereby securing the buttress plate 12 and extending the lower bodyportion 16 over the replaced intervertebral disk. A pair of fangs 32,34, which provide rotational stability, are located along a lip 36 ofthe upper body portion 14 and are equally spaced about the screw hole18. The pair of fangs 32, 34 cooperate with the self tapping screw 30 tofurnish a tripod fixation.

The screw hole 18 includes a counterbore 40 having a beveled surface 42that intersects, at a pinch point 44, a bore 46 having a conical surfaceof revolution 48 that transitions into a bone contacting surface 50 ofthe buttress plate 12. It should be appreciated that the surface ofrevolution 48 may be of a geometry or curvature other than a conicalsurface. The counterbore 40 includes three substantially equallyrotationally spaced contact regions 60, 62, 64 that align with the sidesof an equilateral triangle. Three non-contact regions 66, 68, 70 includethree substantially equally rotationally spaced regions that align witha non-linear cross-section of a cylinder. The contact regions 60-64 andnon-contact regions 66-70 alternate to form a varied surface 72 (SeeFIGS. 8-10), which has 60°, 120°, 180°, and 240° rotational symmetry andthree mirror planes of symmetry.

With respect to the screw 30, the screw 30 is configured to be insertedinto bone. A head region 87 includes a proximal root portion 80 which isconfigured to be secured within the screw hole 18 and an elongated bodyextends therefrom to a distal end having a point 89. The elongated bodymay be a threaded as shown by threaded elongated body 86, in order thatthe engagement of the bone is made stronger. The proximal root portion80 has a sloping radial surface 82 ending in a continuous rib 84 whichradially projects from the screw. The sloping radial surface 82 conformsto the shape of the counterbore 40. The screw 30 further includes asocket 88 in the head region 87 in one implementation.

During a spinal fixation procedure wherein the bone plate 12 has theform of an anterior buttress staple, the bone plating system 10 isutilized following the removal of the intervertebral disc and theinsertion of a spinal implant to stabilize the spinal column. The boneplate 12 is positioned along the spinal column proximate to the spinalimplant to act like a bracket, urging against the spinal implant toprevent the expulsion of the spinal implant from the spinal column. Thepair of fangs 32, 34 are tapped into the bone to hold the bone plate 10in position such that the lower body portion 16 spans across the spinalimplant. As previously mentioned, the visualization window 20 in thelower body portion 16 assists with the placement of the anteriorbuttress staple 10. Additionally, the pair of fangs 32, 34 provide forbipod support that transitions into tripod support with the insertion ofthe screw 30.

The screw 30, which may be a self taping screw, is inserted into thebone through the screw hole 18 which is configured to expand andcontract to alleviate stress and torque during implantation. The pinchpoint 44 provides an interference fit between the screw 30 and the boneplate 12. More particularly, the pinch point 44 flexibly captures thescrew 30 to limit axial travel by a detented engagement between thepinch point 44 and the junction of the sloping radial surface 82 and rib84. The screw hole 18 and the visualization window 20 of the anteriorbuttress plate distribute the compressive and torque loads applied tothe spinal implant or spinal implants inserted between vertebrae.Accordingly, the bone plating system 10 furnishes a stabilization platethat provides a secured-locking mechanism for fixation of anintervertebral disk and a measure of flexibility following implantationas well.

With reference to FIG. 8 through FIG. 10, the varied opening 72 of thescrew hole 18 may be a resilient, flexible opening that provides for theremoval of the bone plate 10 during revision surgery when the bone plate10 is required to be lifted or otherwise removed from the bone. Thenon-contact regions 66-70 provide space between the screw 30 andanterior buttress staple 10 for the manipulation and/or application ofleverage to the screw 30 to assist with the removal of the screw 30 andanterior buttress staple. The contact and non-contact aspects of thevaried opening 72 are presented in FIG. 8 and FIG. 9, wherein in FIG. 8(NB, non-180° cross-section), screw contact, as represented by theletter C, is made with contact region 60 and contact region 62. In FIG.9, however, at the same time as shown by the 180° cross-section, contactis made with contact region 60 and no screw contact, as represented bythe letters NC, is made with non-contact region 68.

More particularly, the varied opening 72, which is depicted as acontinuous surface, provides a variable geometry (See FIG. 10) defininginterleaved and rotationally-spaced contact and non-contact bone screwregions. In one embodiment, the varied opening 72 may oscillate oralternate between providing contact surfaces (e.g., non-contact regions66-70) or contact planes and areas of non-contact which are regionsdisposed in a non-coplanar relationship with the contact planes. Thevaried opening 72 may be, as mentioned, a continuous surface, anuninterrupted surface, or a continuous, uninterrupted surface, forexample.

The screw hole 18 may include any combination of contact and non-contactregions and the number and placement of contact and non-contact regionsare not limited to the previous presentations, wherein three of eachwere depicted and described. Any number of non-contact regions may beinterleaved with any number of contact regions to create the continuoussurface. FIG. 11 depicts such an embodiment of bone plate 110. In thisimplementation, contact regions 112, 114, 116, 118, 120, 122 areseparated by non-contact regions, which include non-contact regions 124,126, 128, 130, 132, 134.

Moreover, the screw hole 18 is not limited to anterior buttress staples,but may be utilized with other types of surgical implant plates as wellregardless of location of installation in the body. That is, the boneplate 12 may take any form and the body may be shaped to conform to anytype of bone including, for example, spinal vertebrae, cranium, maxilla,mandible, clavicle, humerus, acromion, ulna, radius, tarsal, metatarsal,phalange, carpal, metacarpal, ilium, pubic, femur, tibia, fibula,calcaneus, talus, navicular, or cuboid. The bone plate 12 may vary instructure depending on application and, for example, the lower surfacemay be concave along a substantial portion of a longitudinal access ofthe body. Moreover, the bone plate 12 may be used in combination with aninterbody implant, a bone graft, or a bone growth promoting material,for example.

By way of example, FIGS. 12 and 13 depict an anatomically contouredcervical plate with bone ingrowth surfaces, providing for intersegmentalcompressive preloading, and a rigid and locked interface to all of thebone screws by way of screw holes 18. Moreover, as shown, the bone plate140 may be concave along a substantial portion of a longitudinal accessof the body 142.

In this embodiment, similar to the previous embodiments, the bone plate140 includes a body 142 having a thickness and a span sufficient tooverlap a portion of a bone. A lower surface of the bone plate is forplacement against the bone and an upper surface is opposite the lowersurface. The screw hole 18 extends through the body from the uppersurface through the lower surface. The screw hole 18 is adapted toreceive a bone screw to attach for engaging the bone plate 140 to thebone and may be a resilient aperture. The screw hole 18 includes acounterbore having a beveled surface that intersects at a pinch point abore having a conical surface of revolution that transitions into thelower surface. In this embodiment, the varied opening and beveledsurface of the screw hole 18 include a variable geometry defininginterleaved and rotationally-spaced contact and non-contact bone screwregions. As shown, additional screw holes 18 may be utilized in the boneplate.

Byway of another example, a bone plate may have a span that issufficient to overlap a portion of a second bone in addition to thefirst bone. FIG. 14 depicts a bone plate 150 having plate portions 152,154 hingedly connected at hinge 156. The bone plate 150 includes screwholes 18 and joins the fracture of a pelvis. The plate portions 152, 154are placed on either side of the fracture and secured to the bone by wayof screws and screw holes 18.

To further illustrate that the embodiments of the bone plate includingthe screw hole 18 may be used in other plating applications, aspreviously mentioned, FIG. 15 is presented wherein a bond plate 160defines a prosthetic wrist having a radial insert, which is configuredto be fixed to the resected radius of a patient by way of a body 162having a carpal implant 168 and wrist bearing components 164, 166. Inthis bone plate implementation, screw holes 18 are located on thebearing components 164, 168.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

What is claimed is:
 1. A bone plating system adapted for contacting atleast a portion of a bone, the plating system comprising: a plateincluding a body having a span sufficient to overlap a portion of thebone, the body having a lower surface for placement against the bone andan upper surface opposite the lower surface; a screw hole extendingthrough the body from the upper surface through the lower surface, thescrew hole being adapted to receive a bone screw to attach for engagingthe plate to the bone; wherein the screw hole including a counterborehaving a beveled surface that intersects at a pinch point a bore havinga conical surface of revolution that transitions into the lower surface;wherein the beveled surface has a variable geometry defining alternatinglinear contact bone screw regions and arcuate non-contact bone screwregions that are interleaved and rotationally-spaced; wherein thebeveled surface comprises an uninterrupted, circumferentially continuoussurface; a screw configured to be inserted into the bone, the screwhaving a head region configured to be secured within the screw hole andan elongated body extending therefrom to a distal end of the screw, theelongated body including a threaded portion for engaging the bone;wherein the screw includes a proximal root portion of the head region,the proximal root portion having a sloping radial surface ending in acontinuous rib which radially projects from the screw; and wherein thepinch point flexibly captures the screw to limit axial travel by adetented engagement between the pinch point and a junction of thesloping radial surface and the continuous rib.
 2. The plating system asrecited in claim 1, wherein the screw hole comprises a resilientaperture.
 3. The plating system as recited in claim 1, wherein the spanis sufficient to overlap a portion of a second bone.
 4. The platingsystem as recited in claim 1, further comprising at least one additionalscrew hole extending through the body.
 5. The plating system as recitedin claim 1, wherein the lower surface is concave along a substantialportion of a longitudinal access of the body.
 6. The plating system asrecited in claim 1, in combination with an interbody implant.
 7. Theplating system as recited in claim 1, in combination with a bone graft.8. The plating system as recited in claim 1, in combination with a bonegrowth promoting material.
 9. The plating system as recited in claim 1,wherein the body is shaped to conform to a bone selected from the groupconsisting of spinal vertebrae, cranium, maxilla, mandible, clavicle,humerus, acromion, ulna, radius, tarsal, metatarsal, phalange, carpal,metacarpal, ilium, pubic, femur, tibia, fibula, calcaneus, talus,navicular, and cuboid.
 10. A bone plating system adapted for contactingat least a portion of a bone, the plating system comprising: a plateincluding a body having a span sufficient to overlap adjacent vertebralbodies of a spinal column, the body having a lower surface for placementagainst the bone and an upper surface opposite the lower surface, thebody including a figure-8-shape having first and second body portions; ascrew hole extending through the first body portion from the uppersurface through the lower surface, the screw hole being adapted toreceive a bone screw to attach for engaging the plate to the bone;wherein the screw hole including a counterbore having a beveled surfacethat intersects at a pinch point a bore having a conical surface ofrevolution that transitions into the lower surface; wherein the beveledsurface has a variable geometry defining alternating linear contact bonescrew regions and arcuate non-contact bone screw regions that areinterleaved and rotationally-spaced; wherein the beveled surfacecomprises an uninterrupted, circumferentially continuous surface; awindow extending through the second body portion from the upper surfacethrough the lower surface, the window being adapted to provide forvisualization of a portion of the adjacent vertebral bodies; and a pairof fangs coupled to the lower surface of the first body portion, thepair of fangs being equally spaced about the screw hole, the pair offangs for engaging the bone to provide rotational stability; a screwconfigured to be inserted into the bone of one of the vertebral bodies,the screw having a head region configured to be secured within the screwhole and an elongated body extending therefrom to a distal end of thescrew, the elongated body including a threaded portion for engaging thebone; wherein the screw including a proximal root portion of the headregion, the proximal root portion having a sloping radial surface endingin a continuous rib which radially projects from the screw; and whereinthe pinch point flexibly captures the screw to limit axial travel by adetented engagement between the pinch point and a junction of thesloping radial surface and the continuous rib.
 11. The plating system asrecited in claim 10, wherein the body comprises a plurality of screwholes.
 12. The plating system as recited in claim 10, wherein an angleof displacement between the first body portion and the second bodyportion is present to reflect angle of lordosis, including an angle ofcervical lordosis.
 13. The plating system as recited in claim 10,wherein the pair of fangs cooperate with the screw to furnish a tripodfixation.
 14. A bone plate adapted for contacting at least a portion ofa bone, the bone plate comprising: a plate including a body having aspan sufficient to overlap a portion of the bone, the body having alower surface for placement against the bone and an upper surfaceopposite the lower surface; a screw hole extending through the body fromthe upper surface through the lower surface, the screw hole beingadapted to receive a bone screw to attach for engaging the plate to thebone; wherein the screw hole including a counterbore having a beveledsurface that intersects at a pinch point a bore having a conical surfaceof revolution that transitions into the lower surface; wherein thebeveled surface has a variable geometry defining three linear contactbone screw regions and three arcuate non-contact bone screw regions thatare interleaved and rotationally-spaced; wherein the beveled surfacecomprises an uninterrupted, circumferentially continuous surface; andwherein the pinch point is configured to flexibly capture a screw tolimit axial travel by a detented engagement between the pinch point andthe screw.
 15. The bone plate as recited in claim 14, wherein the screwhole comprises a resilient aperture.
 16. The bone plate as recited inclaim 14, wherein the span is sufficient to overlap a portion of asecond bone.
 17. The bone plate as recited in claim 14, furthercomprising at least one additional screw hole extending through thebody.
 18. The bone plate as recited in claim 14, wherein the lowersurface is concave along a substantial portion of a longitudinal accessof the body.
 19. The bone plate as recited in claim 14, in combinationwith an interbody implant.
 20. The bone plate as recited in claim 14, incombination with a bone graft.